System for delivering propane or other consumable liquid to remotely located storage tanks

ABSTRACT

An improved system for delivering propane or other consumable liquid to remotely located storage tanks including a novel combination of remote monitoring of customer tanks and an improved method of using the remote monitoring data to optimally schedule deliveries, improve safety, and more efficiently operate a propane dealership. More accurate and timely information concerning the status of customer tanks serves to improve operational efficiencies and increase safety. Data received from remote sensors can be collected and organized so that it is easily understood and utilized through the implementation of a user interface accessible via the Internet that allows the information to be presented in an efficient graphical and contextual fashion. Operational efficiencies can also be improved by taking historical propane usage for each tank, weather conditions, and projected fuel usage into account. The system can calendar required inspections of customer tanks, homes, and appliances, and data can be combined with accounts receivable information. Remote monitoring of customer tanks can be combined with other products using similar equipment to provide additional non-seasonal revenue streams.

This application claims priority from U.S. application Ser. No.11/097,964, filed on Apr. 1, 2005, which claims the benefit of U.S.Provisional Application No. 60/558,852, filed on Apr. 3, 2004, both ofwhich are hereby incorporated by reference.

TECHNICAL FIELD OF THE INVENTION

The present invention relates to an improved system for deliveringpropane or other consumable liquid to remotely located storage tanks.

BACKGROUND AND SUMMARY OF THE INVENTION

Propane is a gas, a derivative of natural gas and petroleum. It is oneof the many fossil fuels that are included in the liquefied petroleum(LP) gas family. Because propane is the type of LP-gas most commonlyused in the United States, propane and LP-gas are often usedsynonymously.

Under normal atmospheric pressure and temperature, propane is a gas.Under moderate pressure and/or lower temperatures, however, propanechanges into a liquid. Because Propane takes up much less space in itsliquid form, it is easily stored as a liquid in pressurized tanks. Whenpropane vapor (gas) is drawn from a tank, some of the liquid in the tankinstantly vaporizes to replace the vapor that was removed.

Homes and businesses use about one-third of the propane consumed in theU.S. Propane is used mostly in homes in rural areas that do not havenatural gas service. More than 20 million households use propane to meetsome of their energy needs, while 16 million households use propane astheir main heating source. Homes that use propane as a main energysource usually have a large propane tank outside of the house thatstores propane under pressure as a liquid.

Because home space heating is a primary use of propane, demand is muchhigher during the winter months. Residential users of propane typicallyhave a 250-500 gallon tank installed by a local propane dealer andaccessible to delivery trucks for refilling. Depending on the climate, atypical residential tank is filled three to four times per year. Aresidential tank is usually owned by the propane dealer and rented tothe residential customer for an annual fee.

Propane dealers typically operate out of bulk storage plants thatinclude one to two 30,000 gallon storage tanks. A single dealer willusually be able to effectively service a 35 mile radius around theplant, though in less populated regions a much larger service area maybe necessary to achieve sufficient volume. Propane is delivered tocustomers by bulk delivery trucks or “bobtails” which typically holdfrom 1,800 to 3,000 gallons of propane. Customer tanks usually make upthe largest portion of a dealer's assets.

Obviously, different size tanks and different usage rates for customersover a large area can make it very challenging for a dealer to keep allof his customers' tanks filled. The quantity of liquid propane storedand remaining on customer propane tanks needs to be measured frequentlyso that the propane dealer can manage his own inventory of bulk propane,efficiently schedule deliveries, and most importantly keep his customerssupplied with propane. There are also significant safety concernsassociated with propane tank levels since empty or overfilled tanks canbe very dangerous. Further, costs associated with delivery, includingwages for delivery personnel and vehicle operation and fuel costs, are asignificant portion of a dealers's operating expenses. For this reason,dealers must try to maximize the ratio of gallons of delivered propaneper mile traveled by delivery vehicles in order to lower delivery costs.

Traditionally, the standard practice was for propane dealers toperiodically visit each tank and visually read a gauge located on thetank in order to determine whether the tank needed refilling. If thetank level was low, it would be refilled; if not, the delivery truck hadessentially wasted a trip. As could be expected, this highly inefficientpractice contributed to higher costs, both for the dealer and thecustomers.

For this reason, a number of forecasting methods were developed to givedealers a better idea of how much propane a customer was using and whenmore should be delivered. Since propane is primarily used as a heatingfuel, the typical forecasting method involved factoring temperature andhistoric customer usage rates. A Degree Day is a unit used to measurehow cold it has been over a 24 hour period. The base temperature forDegree-Day calculations is 65 degrees. The actual temperature iscompared to the 65° base temperature and if the temperature is lower,the difference is the number of Degree-Days for that day. For example,if the average temperature for a 24 hour period was 60°, that would be5° less than the base temperature of 65°, so we would have 5 Degree-Daysfor that 24 hour period. Another concept, referred to as the K-factor,is used to get an idea of the propane usage rate for a customer. Thecustomer's K-factor is the number of Degree-Days that it takes for agiven customer (or burner(s) associated with a given tank) to use onegallon of propane.

From these two measurements, a dealer could get a better idea as to whenmore propane should be delivered. For example, a customer with a 275gallon propane tank with a historic K-factor of 5 could be expected togo 1375 Degree-Days before the tank is empty. However, since an emptytank is a dangerous condition (plus it means the customer is out offuel) delivery will need to be made before the 1375 Degree-Days haveelapsed. Further, these types of forecasting methods cannot account forunexpected periods of higher or lower than normal propane usage. Sincethis kind of forecasting is merely an estimate, a substantial margin oferror must be built into the delivery schedule. This results in moredeliveries of lower amounts of propane and consequently higher dealerdelivery costs.

For many years, various optimal vehicle routing computer programs havebeen available to minimize the mileage and travel time associated withmaking desired deliveries using vehicles with known capacities. All suchmethods in the prior art, however, necessarily depend upon variousmethods of forecasting a customer's propane usage since the lastdelivery and, as discussed above, such forecasting methods are nevercompletely reliable.

More recently, remote monitoring systems have been used to allow remotetransmission of data relating to the level of the liquid gas containedin customer tanks. This allows for the delivery of fuel or other fluidsto the storage tank on an “as-needed” basis. Such monitoring systems aretypically more accurate than forecasting systems and increase theefficiencies of the propane supplier.

Storage tank monitoring systems currently in use typically include afloat sensor within a storage tank that measures the level of fluid andthe temperature within the storage tank. For remote monitoring systems,data from the sensor is transmitted through some type of communicationnetwork to a data processing unit or display device. Typically, the dataprocessing unit is a computer that decodes and stores the data usingspecialized software. The information received by the data processingunit provides for the monitoring of each specific storage tankindividually.

One remote monitoring system known in the prior art makes use of RFbroadcasting to communicate data from the sensor to the data processingunit. Such systems are relatively inexpensive, however, they have verylimited range. The data processing unit would typically be mounted in adelivery truck which would have to be in the vicinity of the customer'stank for the level to be reported.

Another prior art system uses a modem and ordinary telephone lines tocommunicate data from the sensor to the data processing unit. Typically,such a system will use the modem to call in and signal the dataprocessing unit when the propane in a tank reaches a pre-determinedlevel. The customer's phone line must be free for the system to work.

Other prior art systems used to monitor liquid volume in tanks make useof satellite or cellular communications. However, each of these systemsalso suffers from disadvantages in certain circumstances. For example,many satellite systems require an externally mounted satellite dish withthe proper exposure. Additionally, two-way communication requiresexpensive equipment and installation. Cellular systems are not practicalin certain locations due to a lack of cellular coverage.

No matter which communication scheme is used, the data received from thesensor is often confusing and can require significant time to decode andformat into a useful form. Even then, it is still difficult for a dealerto interpret the data or use the information to optimally organize histrucks and routes. Further, a dealer must be able to access the dataprocessing unit in order to make use of the data, and this typicallyrequires that the dealer be physically in his office in order to monitorhis business. Also, certain tank conditions, such as an over-fill,require immediate attention. For events occurring outside ordinarybusiness hours, either the dealer must have an employee monitoring thesystem 24 hours a day or else these events will not be corrected untilthe next business day.

Propane dealers also face economic challenges arising from the seasonalnature of propane demand. As discussed above, demand for propane is highduring the winter months, but much lower during summer. The propanedealer has a significant investment in tanks, trucks, employees, andinfrastructure, and yet he receives a poor return on this investmentduring periods of low demand.

What is needed is a system that combines remotely monitoring levels incustomer tanks with an improved method of using the remote monitoringdata to optimally schedule deliveries and more efficiently operate apropane dealership. Additionally, there is a need for a way to combinesuch an improved operational method with additional revenue streams thatmake use of the same infrastructure to generate additional revenueespecially during periods when propane demand is low.

SUMMARY OF THE INVENTION

An object of the invention, therefore, is to provide an improved systemfor delivering propane or other consumable liquid to remotely locatedstorage tanks. This goal is achieved through a novel combination ofremote monitoring of customer tanks and an improved method of using theremote monitoring data to optimally schedule deliveries, improve safety,and more efficiently operate a propane dealership.

The foregoing has outlined rather broadly the features and technicaladvantages of the present invention in order that the detaileddescription of the invention that follows may be better understood.Additional features and advantages of the invention will be describedhereinafter. It should be appreciated by those skilled in the art thatthe conception and specific embodiments disclosed may be readilyutilized as a basis for modifying or designing other structures forcarrying out the same purposes of the present invention. It should alsobe realized by those skilled in the art that such equivalentconstructions do not depart from the spirit and scope of the inventionas set forth in the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

For a more complete understanding of the present invention, and theadvantages thereof, reference is now made to the following descriptionstaken in conjunction with the accompanying drawings, in which:

FIG. 1 shows a preferred embodiment of a remote propane monitoringsystem according to the present invention where a cellular communicationscheme is employed.

FIG. 2 shows a preferred embodiment of a remote propane monitoringsystem according to the present invention where a satellitecommunication scheme is employed.

FIG. 3 shows a typical prior art liquid storage tank and float gauge.

FIG. 4 shows a preferred embodiment of a monitoring unit for use with acellular communication scheme.

FIG. 5 is a typical delivery schedule screen according to the presentinvention.

FIG. 6 is a typical delivery truck routing screen according to thepresent invention.

FIG. 7 is a daily posted customer tank inventory chart according to thepresent invention.

FIG. 8A is a geographic satellite view of a dealer's customer tanks andtheir current levels.

FIG. 8B is the geographic satellite view of claim 8A zoomed in to showan individual customer.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

A preferred embodiment of this invention provides a novel system andmethod for an improved system to coordinating the delivery of a liquidto remotely located storage tanks.

In accordance with another aspect of a preferred embodiment of thepresent invention, an agnostic communication scheme can be used forremote monitoring of liquid gas levels in storage tanks. Thus,communication does not have to be limited to a single communicationplatform. Any known suitable communication scheme can be employed totransmit data, such as cellular, land phone lines, wireless, satellite,cable, etc. Different communication schemes can be employed fordifferent customers or tank locations, depending on which scheme isoptimal for the individual client or location. Selection of an optimalcommunication network can be based upon factors such as location,availability of cellular signal, availability of telephone lines, anddesired equipment investment by customer.

FIG. 1 shows one aspect of a preferred embodiment of a remote propanemonitoring system 100 according to the present invention where acellular communication scheme is employed to transfer data between astorage tank monitoring unit and the central server. Remote propanemonitoring system 100 comprises central processing station 102 whichcommunicates with a plurality of monitoring units 107 located atcustomer sites 106 by way of one or more cellular towers 104.Communication between central server 102 and monitoring units 107 ispreferably two-way communication. As discussed in greater detail below,monitoring units collect data from the propane tank sensor andoptionally from one or more home monitoring sensors 108 and transferfluid level data to the central server 102. Data can then be organizedand processed (as also discussed below) and transferred from centralserver 102 through satellite up-link 128 to satellite 110 and/or throughweb server 124 to the Internet or a suitable intranet. Central server102 can comprise one or more computers at one or more locations.End-user 130 can then access data through a wireless satellite link orthrough the Internet, for example by using a personal computer withInternet access. Central server 102 can also communicate with deliverytrucks 140 by way of cellular towers 104.

FIG. 2 shows another preferred embodiment of a remote propane monitoringsystem 200 according to the present invention where a satellitecommunication scheme is employed to transfer data between a storage tankmonitoring unit and the central server. Remote propane monitoring system200 comprises central server 102 which communicates with a plurality ofmonitoring units 207 located at customer sites 106 by way of satellite210. Monitoring units 207 can communicate with satellite 210 by way of asatellite modem and antenna (not shown). In the embodiment shown in FIG.2 communication is one-way from the monitoring units 207 to thesatellite 210. Even more preferably, however, communication betweenmonitoring units 207 and satellite 210 can be two-way communication. Asdiscussed in greater detail below, monitoring units collect data fromthe propane tank sensor and optionally from one or more home monitoringsensors 108 and transfer fluid level data to the satellite 210. Data isthen transferred to central server 102 by way of satellite up-link 228.Data can then be organized and processed (as also discussed below) andtransferred from central server 102 through web server 224 to theInternet or a suitable intranet. End-user 130 can then access datathrough the Internet or suitable intranet, for example by using apersonal computer with Internet access. Optionally, monitoring units ondelivery trucks 140 can also communicate with the central server 102 byway of the satellite 210 and satellite up-link 228.

Tank levels can be monitored by a number of different mechanisms knownin the prior art. For example, one common type of gauge is known as afloat gauge. As the name suggests, a float gauge has a float that restson the surface of the fluid being measured. The position of the floatwill rise or fall as the level of liquid in the tank is changed.Movement of the float is sensed by a gauge, typically through the use ofa magnetic coupling, to provide an indication, either visual orotherwise, of the fluid level. A typical float gauge and propane tankcombination 300 is shown in FIG. 3. Float assembly 302 is mounted insidetank 304. As illustrated in FIG. 3, the position of float 306 will varywith the liquid levels 308 and 310 in the tank. The float assembly 302represents the attachment mechanism through which the sensor unit of thepresent invention detects the level of the propane inside the tanks.Vertical movement of the float as it follows the level of the liquid isconverted into rotational movement by a pinion 312 which rotates a shaftextending inside tube 314 and turns a master magnet 316. The floatassembly 302 attaches by the float head 318 under a pressure seal. Adial gauge 320 is mounted onto the float head 318.

The dial gauge 320 will preferably comprise a dial chamber with a remotesender that gives a visual indication of tank levels while also sendingan electrical signal to a monitoring unit. This electrical signal servesto give a remote indication of the tank levels.

FIG. 4 shows a preferred embodiment of a local customer monitoringsystem 400 according to the present invention. Monitoring unit 401comprises a sealed case 403 containing processor 402 and at least oneassociated communication device 404, such as a cellular modem, linemodem or satellite communication device. Communication device 404 can beconnected to external antenna 424. Processor 402 and associatedcommunication device 404 are preferably powered by batteries 422 oroptional external power supply 423, and communicate with one or morepropane tank sensors 412 through I/O port 405. Status andtroubleshooting information can be displayed externally via LEDs 408.

Processor 402 comprises circuitry for implementing the followingfunctions: receiving data from the one or more propane tank sensors 412:processing the data, and converting it into readable form if necessary;at preselected intervals or times, connecting to the central server (notshown) through the associated communication device 404 and externalantenna 424 to transfer collected data; and determining whetherpredefined conditions have occurred, such as a low liquid level or anoverfill, or whether predefined abnormal or “out of ordinary” eventshave occurred, such as liquid levels dropping too fast (possiblyindicating a leak) or not dropping at all (indicating a possible problemwith the tank sensor). Skilled persons will recognize that saidcircuitry can be implemented with conventional processors and/orcontrollers, integrated circuits, discrete devices, or any combinationof the same.

Processor 402 can communicate with tank level sensor 412 by way of adirect wire connection 418, I/O port 406, and communication bus 405. Ina preferred embodiment, a second I/O port allows for X-10 functionalityas discussed below. Processor 402 can also communicate with a pluralityof additional secondary sensors. For example, data can be collected fromone or more home monitoring sensors 421 capable of detecting CarbonMonoxide, propane gas, or variations in temperature inside thecustomer's home. Data from these types of additional sensors can betransmitted to the central server along with data on propane tanklevels. Communication between monitoring unit 401 and home monitoringsensors 421 can be through any appropriate means, including X-10, RF, ordirect wiring.

Preferably case 403 will be sealed to protect the sending unit fromadverse environmental conditions. In the event of mechanical failure,the entire unit can be easily replaced. In a preferred embodiment, themonitoring unit of FIG. 4 will also provide I/O functionality (includingdata ports allowing the monitoring unit to communicate with X-10 devicesor the customer's personal computer). Although any appropriatecommunication device can be used with the present invention, in apreferred embodiment the unit will have a primary communication device,such as a cellular modem, and a backup device, such as a land linemodem.

Monitoring unit 401 can be operated by any appropriate power source,including direct wiring, battery packs, or solar chargers. Depending onthe power source, the communication device can be configured to operatein different modes. Preferably, for example, a monitoring unit whichuses a radio (RF) transmitter and is powered by a battery pack would beconfigured so that the radio is powered off most of the time in order toconserve power. Processor 402 would periodically wake up the radio sothat incoming commands can be received.

In a preferred embodiment, monitoring unit 401 could collect data andreport to the central server once per day at a particular time, forexample at 3:00 a.m. In the case of cellular transmission, this wouldtypically allow a dealer to negotiate a cheaper cellular rate plan sincemost transmissions will not occur during peak cellular times. If landline communication is used, reporting at 3:00 a.m. should limit thepotential interference with the customer's use of the telephone line.Additionally, as discussed above, monitoring unit could be configured toreport immediately if certain types of conditions occur, including forexample, overfilled tanks, greater than expected usage (which couldindicate a leak), low battery, or any other “out of ordinary” condition.

In accordance with another aspect of a preferred embodiment of thepresent invention, data can be queued until it is reported. This wouldallow the collection of very detailed data, for example hourly tanklevels, while minimizing connect time. This would also allow thecommunication system to be more tolerant of communication faults sincedata would be stored until a satisfactory communication is established.

In accordance with another aspect of a preferred embodiment of thepresent invention, data received from the tank sensors can be collectedand organized so that it is easily understood and utilized by thepropane dealer through the implementation of a user interface whichallows the propane dealer to see each customer's current status in agraphical and contextual way. This improves the ability of the propanedealer to analyze and react to data quickly and easily without thenecessity of reviewing voluminous data which is not organized in anoptimum order.

For example, in a preferred embodiment, basic information and historywould be accessible for each customer or each storage tank. Acolor-coded tank inventory can be graphically displayed so that a dealercan see a list of customers and tank levels and at a glance tell thestatus of each customer's tank. FIG. 5 is a typical delivery scheduleaccording to the present invention. This screen shows the deliveryvehicles selected for use and the customers scheduled for delivery. In apreferred embodiment, a program running on the central server makes theselection according to user-defined criteria. An authorized user canoverride the program's selections from this screen. A customer tankinventory is graphically displayed so that fluid levels can be easilyseen. Tanks with sufficient propane levels can be indicated with aselected screen color, for example with icons or graphical shapes of aparticular color. Tanks which need refilling can be shown through theuse of a different screen color. Over-filled tanks can be shown throughthe use of a third screen color.

FIG. 6 is a typical delivery truck routing screen according to thepresent invention. Each stop on the scheduled delivery route is shown inorder with the physical address, tank capacity, and scheduled deliveryamount. Estimated time of delivery and distance between stops can alsobe shown.

A daily posted customer tank inventory chart, as illustrated in FIG. 7,will preferably allow the dealer to recognize customer use trends anddetect any anomalies, such as an unauthorized tank fill or pump-out.This chart graphically displays the fluid level in a customer's tankover a defined time period, for example over a four month period. Thisallows the dealer to immediately identify the refill dates and to see ifthere is any drastic change in usage rates.

In accordance with another aspect of a preferred embodiment of thepresent invention, color-coded data can also be displayed on a map thatshows the location and status of each tank. This would also provide foreasy printing of routes and customer locations for drivers. Datareceived from customer tanks would automatically be used to createcolor-coded liquid level tank information lists accessible by thepropane dealer. Custom color-coded maps showing customer locations oneach delivery route can be accessed via the Internet and displayed to aPC screen and printed by delivery personnel. This allows a dealer tohave a geographic or “satellite” view of all of his customer tanks andcurrent levels and to map delivery routes that most efficiently utilizethe dealer's assets and ensure that customer needs are met. Preferably,maps will be able to show an entire customer base, as shown in FIG. 8A,or zoom in on a particular customer or route, as shown in FIG. 8B.

In accordance with another aspect of a preferred embodiment of thepresent invention, tank sensor data can be used to calculate the mostefficient delivery truck routes. It is desirable to determine how muchpropane to load onto each truck, and what stops to deliver in a costefficient manner. Utilizing relevant information, such as tank leveldata received from customers, information on delivery trucks and sizes,availability of trucks, and delivery location points, an adaptivealgorithm would preferably match the needs of the customer database withthe available delivery trucks and model the most efficient routes foreach available truck. By increasing efficiency, dealers can make moreeconomical use of their equipment and employees and can maximize gallonsper mile and gallons per stop ratios. The modeling could also bepredictive by taking historical propane usage for each tank, weatherconditions, and projected fuel usage into account in determining whichtanks should be refilled along a given delivery route. Historic, DegreeDay, and Julian (Elapsed) Day forecasting can also be taken intoaccount. A preferred embodiment could also include a scheduling systemthat would use the optimum route determination to provide fill tickets(specifying how much propane is to be loaded onto each truck) to thestaff responsible for filling up each truck in the morning and toprovide routing and delivery instructions for each driver.

In accordance with another aspect of a preferred embodiment of thepresent invention, the system can calendar required inspections ofcustomer tanks, homes, and appliances, as required by industrystandards, either after an event, such as an out of gas situation, orafter a proscribed period of time as passed. The volatile nature ofpropane gas creates the potential for serious ramifications to occurshould a leaking pipe or joint develop. Dangerous conditions may alsoexist where appliances or heating units with open flames are exposed touncontrolled fuel. Pressure testing the entire propane system,inspecting the tank, piping, regulator, gauges, connectors, valves,vents, thermostats, pilots, burners and appliance controls on a regularschedule or after an out of ordinary event occurs can significantlyreduce the possibility of loss of life or property damage. The systemwill have the capability to alert the propane dealer and drivers to theneed to perform required testing either on a regular timed basis orafter the occurrence of an out of ordinary event.

In accordance with another aspect of a preferred embodiment of thepresent invention, data (in the form of customer information, tankinventories, or delivery information) can be combined with accountsreceivable information. Customer accounts receivable balances can bedisplayed on a PC screen organized by route, or printed out on thecolor-coded route sheets discussed above. This preferably allows thedealer to arrange for payment before or on delivery or to reconfigurethe delivery route where satisfactory payment arrangements cannot bemade with customer.

One aspect of a preferred embodiment of the present invention isdirected to a Web-based (Internet and Intranet) client-serverapplication that enables dealers to access information relating to themonitoring of their propane tanks and inventories, along withinformation related to additional income producing services as discussedbelow. Data from remote sensors, along with the graphical and contextualorganization of that data as discussed above, would thus preferably beavailable to end-users (for example, the propane dealer) by way of theInternet, or a LAN, WAN, or the like.

The end-user could choose to dedicate a computer monitor or monitors tothe continually updated display of such information. Information may bestored on either the central server, a web server, or the end-userscomputer so that historical patterns and trends can be identified.

Additionally, dealers are preferably able to monitor, via a Web browserinterface and in real-time, any alarms or out-of-ordinary eventsaffecting their customers or business. In a preferred embodiment, alarmnotices—such as a tank overfill notice, tank low level notice, anout-of-ordinary occurrence, or a variance from historic or Degree Daydata and projections—can be posted on the Dealer log-in page. The dealercan also be notified of alarms by pager, text messaging, or email.

In accordance with another aspect of a preferred embodiment of thepresent invention, the use of interactive web-based managed servicessoftware, accessible by a number of dealers through individual passcodeprotected Web-site links, allows for across-the-board system upgradesand enhancements without requiring massive hardware or CD mailings.

In accordance with another aspect of a preferred embodiment of thepresent invention, the system for remote tank monitoring of propanetanks can be combined with other products using similar equipment inorder to provide the propane dealer with additional non-seasonal revenuestreams. As discussed above, propane business is seasonal, with highestdemand occurring during the winter months. Although expensive monitoringequipment, which can include satellite, cellular, and land-linecommunication systems, is used primarily during periods of high demand,the equipment remains at the customer's location throughout the year.Similarly, a propane business will typically require a staff with agreat deal of technical expertise, but that expertise is generally onlyput to use during high demand periods. During the off-season, thesehighly trained employees will typically be used for numerousnon-technical tasks.

According to the present invention, a propane dealer can take advantageof the expertise of his employees and the existing monitoring equipmentinfrastructure to provide additional services to customers. For example,the equipment used for satellite communication of remote tank levels canalso be used to provide a customer with satellite television or Internetservice. The same employees who install and service satellite monitoringsystems will be able to use their technical expertise to install andservice satellite entertainment services.

In a preferred embodiment, X-10 functionality on the monitoring unitallows home monitoring and automation services to be transmitted withthe same equipment used for tank monitoring (even where satelliteequipment is not installed or is not available.) As is well known tothose of ordinary skill in the art, the term X-10 refers to astandardized protocol accepted as an industry standard for communicationbetween devices via AC power lines within a single facility. X-10communicates between transmitters and receivers by sending and receivingsignals over the AC power line wiring. These signals involve short RFbursts, which represent digital information. This X-10 functionality canbe controlled by way of the customer's PC, and can easily be accessedthrough the Internet. As discussed above, in a preferred embodiment, themonitoring unit will have a port allowing the processor to interfacewith home monitoring sensors, such as X-10 devices. Other types ofcommunication protocols and connections could also be used to connecthome monitoring sensors to the monitoring unit, including wireless RFtransmission or hard wired connections. This allows the propane dealerto also offer, for a relatively small equipment and training investment,home security and fire monitoring, home automation, and specializedmonitoring which is desirable for propane customers such as CarbonMonoxide and propane gas monitoring inside the home.

By combining wireless entertainment and X-10 functionality with the tankmonitoring system discussed herein, both monitoring and additionalrevenue-producing services preferably benefit from cost savings andincreased efficiencies.

In accordance with another aspect of a preferred embodiment of thepresent invention, where more than one type of tank monitoringcommunication scheme could be used, the communication scheme can bematched to additional services desired by the customer, thus creatingadditional efficiencies and cost savings. For example, where thecustomer wishes to purchase satellite television or Internet services,the same satellite equipment could be used to provide the communicationbetween the monitoring sensors and the data server.

Particular embodiments of the present invention are directed to animproved system and method for coordinating the delivery of a consumableliquid to remotely located storage tanks. Although much of the followingdescription is directed toward propane storage and delivery, the presentinvention could be utilized with any type of consumable liquid commonlystored in liquid storage tanks, including natural gas or anhydrousammonia. Hence, the scope of the present invention should not be limitedto propane storage and delivery. Further, although much of thisdiscussion is directed an economic model including a propane dealerservicing propane tanks located at customer sites, the system andmethods discussed herein would be equally applicable to differenteconomic models, including for example, a large corporation or otherbusiness entity servicing a large number of remote storage tanks fromone or more central storage facilities.

Although the present invention and its advantages have been described indetail, it should be understood that various changes, substitutions andalterations can be made to the embodiments described herein withoutdeparting from the spirit and scope of the invention as defined by theappended claims. Moreover, the scope of the present application is notintended to be limited to the particular embodiments of the process,machine, manufacture, composition of matter, means, methods and stepsdescribed in the specification. As one of ordinary skill in the art willreadily appreciate from the disclosure of the present invention,processes, machines, manufacture, compositions of matter, means,methods, or steps, presently existing or later to be developed thatperform substantially the same function or achieve substantially thesame result as the corresponding embodiments described herein may beutilized according to the present invention. Accordingly, the appendedclaims are intended to include within their scope such processes,machines, manufacture, compositions of matter, means, methods, or steps.

1. A system for coordinating the delivery of a consumable liquid to twoor more remotely located storage tanks at several different locationscomprising: at least one monitoring unit associated with each storagetank to be in close proximity to the storage tank and communicativelylinked with a sensor that provides fluid level information indicative ofthe amount of fluid in the storage tank, wherein each monitoring unitincludes at least one processor to receive and process the receivedfluid level information; at least one central server remotely locatedfrom the two or more storage tanks to be communicatively linked witheach monitoring unit; wherein each monitoring unit is capable ofprocessing fluid level information to determine whether a predefinedout-of-ordinary event has occurred and, if so, send notice to the atleast one central server; and the at least one central server to processreceived fluid level information (i) to provide displayable fluid leveldata, (ii) to forecast future fluid levels utilizing at least storedfluid level data, (iii) to determine a delivery schedule based at leaston tank capacities, fluid levels, and an inventory of one or moredelivery vehicles, and (iv) to provide one or more routes for thedelivery vehicles to reach the storage tanks based at least on tanklocation and an amount of fluid to be delivered.
 2. The system of claim1 further comprising a graphical user interface configured to downloadinformation to be displayed and to allow user input.
 3. The system ofclaim 2 wherein the graphical user interface is an Internet web browser.4. The system of claim 1 wherein an adaptive algorithm is used togenerate an optimal delivery schedule and optimal routing for deliveryvehicles based at least upon fluid level information from remotelylocated storage tanks.
 5. The system of claim 4 wherein the generationof an optimal delivery schedule and optimal routing for deliveryvehicles is also based at least upon maximizing the number of fluidgallons delivered per mile traveled by delivery vehicles executing aroute.
 6. The system of claim 1 wherein said communications linkcomprises a cellular modem, a satellite communication system, a modemand telephone line, or an RF transmitter/receiver.
 7. The system ofclaim 1 wherein said communications link comprises a primarycommunications link and a backup communications link to be used if theprimary communications link is not operable.
 8. The system of claim 1wherein said determining whether a predefined out-of-ordinary event hasoccurred comprises comparing current fluid level to predefinedthresholds or stored historic fluid levels to determine whether fluidlevels are too high, too low, or whether fluid levels are falling toofast or not falling fast enough.
 9. The system of claim 1 furthercomprising: one or more secondary sensors for detecting the occurrenceof a local phenomena and transmitting a detection signal to at least onemonitoring unit; one or more of the monitoring units being capable ofreceiving a detection signal from secondary sensors, processing thesignal, and sending data concerning the detection signal through acommunications link to the central server.
 10. The system of claim 9further comprising an audible alarm that sounds when said detectionsignal is transmitted by a secondary sensor.
 11. The system of claim 9wherein said one or more secondary sensors are capable of detectinglocal temperature, the presence of propane gas, or higher than normallevels of carbon monoxide.
 12. The system of claim 9 wherein one or moresecondary sensors transmit data to a monitoring unit via X-10, radiofrequency, infrared signals, or hard-wired connection.
 13. The system ofclaim 1 wherein data to be sent from the monitoring unit to the centralserver is queued until a predetermined connect time.
 14. The system ofclaim 1 wherein said central server comprises one or more computers atone or more physical locations executing software.
 15. The system ofclaim 1 wherein information concerning fluid level data is organized anddisplayed graphically.
 16. The system of claim 15 wherein displayinginformation graphically comprises displaying a tank inventory listingcustomers and corresponding fluid levels with levels above or belowpredetermined thresholds color-coded so that particular fluid ranges canbe easily identified.
 17. The system of claim 15 wherein displayinginformation graphically comprises displaying alarm messages whenever aremote monitoring unit has notified the central server that a predefinedout-of-ordinary event has occurred.
 18. The system of claim 17 furthercomprising sending alarm messages via pager, text messages, or emailwhenever a remote monitoring unit has notified the central server that apredefined out-of-ordinary event has occurred. 19-20. (canceled)
 21. Asystem for coordinating the delivery of propane to two or more remotelylocated storage tanks at several different locations via deliveryvehicles, comprising: at least one monitoring unit associated with eachstorage tank to be in close proximity to the storage tank andcommunicatively linked with a sensor that provides fluid levelinformation indicative of the amount of propane in the storage tank,wherein each monitoring unit includes at least one processor to receiveand process the received fluid level information; at least one centralserver remotely located from the two or more storage tanks to becommunicatively linked with each monitoring unit; one or more secondarysensors capable of detecting local temperature, the presence of propanegas, or higher than normal levels of carbon monoxide and transmitting adetection signal to at least one monitoring unit; wherein at least onemonitoring unit is capable of (i) processing propane level informationto determine whether a predefined out-of-ordinary event has occurredand, if so, sending notice to the at least one central server, (ii)receiving a detection signal from a secondary sensor, processing thesignal to determine whether the value is outside a predetermined rangeand, if so, sending data concerning the detection signal through acommunications link to the central server; the at least one centralserver to: (a) process received propane level information to providedisplayable fluid level data, (b) forecast future propane levelsutilizing at least stored historic propane level data, (c) determinebased at least upon propane level information from remotely locatedstorage tanks and maximizing the number of propane gallons delivered permile traveled by delivery vehicles (i) an optimum delivery schedule alsobased at least on tank capacities, propane levels, and an inventory ofone or more delivery vehicles, and (ii) one or more optimum routes forthe delivery vehicles to reach the storage tanks also based at least ondelivery vehicle capacity, tank location, and an amount of propane to bedelivered; a graphical user interface connected to the at least onecentral server via the Internet and configured to allow user input andto download information to be displayed so that (i) informationconcerning propane level data is organized and displayed graphically,(ii) information is at least displayed as a tank inventory listingcustomers and corresponding propane levels with levels above or belowpredetermined thresholds color-coded so that particular propane rangescan be easily identified, and (iii) alarm messages are displayedwhenever a remote monitoring unit has notified the central server that apredefined out-of-ordinary event has occurred or that a secondary sensorhas detected a value is outside a predetermined range.
 22. An apparatusfor coordinating the delivery of a consumable liquid to two or moreremotely located storage tanks at several different locations viadelivery vehicles, comprising: a means for obtaining data indicative ofthe amount of fluid in a storage tank; a means for locally processingthe data to determine whether predefined conditions are met; a means fortransferring the data to a central location; a means for processing thedata at the central location to (i) to provide displayable fluid leveldata, (ii) to forecast future fluid levels utilizing at least storedfluid level data, (iii) to determine a delivery schedule based at leaston tank capacities, fluid levels, and an inventory of one or moredelivery vehicles, and (iv) to provide one or more routes for thedelivery vehicles to reach the storage tanks based at least on tanklocation and an amount of fluid to be delivered.